Conversion of loft space involving alterations to existing roofline and a dormer extension at rear and at front

Appeal Decision Site visit made on 31 March 2026 by S. Burch BSc MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 10 April 2026 Appeal Ref: 6004113 16 Briar Lane, Carshalton, Sutton SM5 4PX • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission. • The appeal is made by Mr Ganesh Diwan against the decision of the Council of the London Borough of Sutton. • The application Ref is DM2025/01213. • The development proposed is the conversion of loft space involving alterations to existing roofline and a dormer extension at rear and at front. Decision 1. The appeal is allowed and planning permission is granted for the conversion of loft space involving alterations to existing roofline and a dormer extension at rear and at front at 16 Briar Lane, Carshalton, Sutton SM5 4PX in accordance with the terms of the application, Ref DM2025/01213, and the plans submitted with it, subject to the following conditions: 1) The development hereby permitted shall begin not later than three years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved plans: • Existing and Proposed Section at AA’, Drg No. 16-11 • Proposed Roof Plan, Drg No.16-10 Revision D • Proposed Ground Floor Plan, Drg No. 16-6 Revision A • Proposed Elevation A & B, Drg No. 16-9 Revision D • Existing & Proposed Section at AA’ & BB’, Drg No. 16-4 Revision C • Proposed Loft Plan, Drg No. 16-7 Revision E • Proposed Front & Rear Elevation, Drg No. 16-8 Revision E 3) The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those as specified in the application form. Preliminary Matters 2. For reasons of precision, I have taken the description of development used in the heading above and in my formal decision from the Council’s decision notice. This accurately describes all aspects of the proposed development and is used in the appellant’s appeal statement of case. Appeal Decision 6004113 2 Main Issue 3. The main issue in this appeal is the effect of the proposed development on the character and appearance of the area. Reasons 4. The appeal site comprises a detached bungalow. The property benefits from parking to the frontage and a generously sized rear garden. The site slopes downwards slightly from the road. The surrounding area is predominately residential in character, with a mix of bungalows and two storey dwellings of varying sizes and styles. The immediate vicinity includes properties that have been extended and altered over time, including examples of loft conversions, roof alterations and substantial dormers. 5. The scheme seeks to increase the height of the existing roof ridge and extend to the side at roof level. It would also incorporate a front and rear roof dormer. 6. The Design of Residential Extensions Supplementary Planning Document (SPD) sets out that dormers should be set below the ridge and away from the hip to avoid visual crowding. They should also not cover the entire roof. The proposed rear dormer would not meet these criteria, as it would be in line with the ridge height of the dwelling and not set away from the hips of the roof. 7. Notwithstanding the above, the existing dwelling is smaller in height than many others in the surrounding area. Additionally, the site slopes slightly downwards from the road, reducing the prominence of the dwelling when viewed from within the street scene. In this regard, the proposed works, which include marginally increasing the overall ridge height of the dwelling, would not appear excessive or overly prominent when viewed from within the street scene and within the context of surrounding development. Also, as demonstrated in the appellant’s evidence, the existing ridge height sits lower than that of both neighbouring dwellings (No’s 14 and 18 Briar Lane). The increased ridge height would therefore be broadly in line with that of its neighbours, in accordance with the guidance in Creating Locally Distinctive Places Supplementary Planning Document. 8. Whilst the rear dormer would sit in line with the increased ridge height, this is not uncommon with the surrounding area. As evident on my site visit and illustrated in the appellants evidence, the property directly to the rear of the appeal site (No.58 Mount Park) benefits from a large rear dormer that sits broadly in line with its ridge height. There are also several other examples of similar developments in the area, as set out in the appellant’s evidence. In this regard, the dormer would not appear incongruous or out of keeping with surrounding development. 9. Whilst the dormer would extend beyond the hips of the roof, this is largely due to the roof form of the property, which narrows in width towards the top. It would be well set in from the sides of the property, ensuring it is proportionate to the main dwelling and reducing its prominence when viewed within the street scene. Additionally, this positioning, coupled with the set in from the eaves would prevent it appearing as an additional storey when viewed from the rear. The property would clearly read as a bungalow, with accommodation in the roof, within the street scene. The rear dormer would also be comparable to the development at 4 Briar Banks (Ref: D2013/67688/CPU), as illustrated by the appellant. Appeal Decision 6004113 3 10. Whilst I acknowledge that some of the examples in the area may have come about through permitted development rights, such dormers, given the number of them, are now established features to the extent that the introduction of another large rear dormer would not be out of character with this locality. 11. The Council raise no concerns regarding the proposed front dormer. I see no reason to disagree with this. 12. Overall, for the reasons set out, I conclude that the scheme would have an acceptable effect on the character and appearance of the area. It would be in accordance with Policy 28 of the Sutton Local Plan 2016-2031. This policy seeks to ensure that new development respects the local context and responds to local character. 13. The absence of any material conflict with the development plan and the avoidance of visual harm together outweighs the conflict with the guidance in the SPD. A departure from the SPD is therefore justified for the reasons previously stated relating to the specific circumstances of the property and its surroundings. Conditions 14. In addition to the standard time limit condition, I have used a condition to specify the approved plans, for the avoidance of doubt and in the interests of certainty. A condition to control the external materials of the development is also necessary in the interests of the character and appearance of the area. 15. The Council’s case officer report outlines how all applications are required to meet the highest standards of fire safety, and had the application been acceptable, details would have been secured by condition. However, my attention has not been drawn to a specific policy which requires such information. The Council has also not suggested this condition in its appeal questionnaire. I therefore cannot be sure that such a condition would meet the tests, as set out in the National Planning Policy Framework and Planning Practice Guidance, in that it would be reasonable and necessary. I have therefore not attached a condition requiring details of fire safety. Conclusion 16. For the above reasons, the proposal accords with the development plan and there are no material considerations that outweigh this finding. Accordingly, the appeal is allowed. S.Burch INSPECTOR